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Question:

is there any difference between a a coupled inductor and a transformer?

:)please be as explicit as possible.Thanks!

Answer:

I guess a coupled inductor would be where two separate inductors are mounted near each other so that they couple. It can't be called a transformer because there isn't a single device. I have never seen this used deliberately, but it could be a handy trick if you need an adjustable coupling by bending one of the inductors. Best of luck getting it past AutoCad. The difference from a transformer is that a transformer is a single device with two or more windings. I think a coupled inductor is two or more separate windings that are mounted near each other.
A transformer implies that there is no deliberate leakage inductance although this is exactly what a self protecting transformer uses. Transformers rarely specify the winding inductance, which has to be high enough to limit the idle current to a small part of the rated current. Instead the voltage and operating frequency are given. This also covers other core loss issues. Florescent ballasts are transformers with significant leakage inductance to limit the current when the gas ionizes.
No, that's the way you model a transformer in SPICE. You do need to make the primary inductance large enough so that the no load (magnetizing) current is no more than 10 to 15% of the full load current.
Coupled inductors are transformers. In electric circuits coupled inductors are the next step after inductors in circuit analysis. Mutual inductance which is the voltage generated in second inductor by changing current is taught. Coupled circuits analyses is used in RF circuits. Coupled inductors may not be tightly coupled whereas transformers especially power transformers the coupling coefficient is very nearly 1. RF circuits may use lose coupling. And transformers especially power transformers are usually not analyzed the same way.

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